Yarn tensioning means for knitting machines



April 19, 1938. E. J. BERGER 2,114,647

YARN TENSIONING MEANS FOR KNITTING MACHINES Filed July 2, 1957 2Sheets-Sheet 1 7 FIG Z WITNESSES- INVENTOR:

Emii I Beryez;

ATTORNEYS.

April 19, 1938. E? J BERGER 2,114,647

YARN TENSIONING MEANS FOR KNITTING MACHINES Filed July 2, 1937 2Sheets-Sheet 2 W1 TNESSES; INVENTOR:

ORNEYS.

6 By Emil JBeTgez;

Patented Apr. 19, 1938 YARN TENSIONING MA Emil J. Berger, Hatfield,Hosiery Mills, Lansda Pennsylvania MEANS FOR KNITTING CHINES Pa,assignor to lDexdale le, Pa., a corporation of Application July 2, 1937,Serial No. 151,617

l Claims.

This inventionrelates to yarn tensions for knitting machines; and it hasreference more particularly to yarn tensioning means for flat knittingmachines of the Cotton type such as are universally used in theproduction of full fashioned stockings and the like. In knittingmachines of the kind specifically referred to, the tension on the yarnsmust be increased as the yarn carriers approach the limits of theirtravel in opposite directions in order to prevent the formation of looseselvage loops along the edges of the stocking blanks. This function isordinarily performed by what are known as snappers which have the formof flat finger-like elelil merits mounted on rock shafts actuated fromthe main cam shaft of the machine and which by cooperation with flatspring tongues pinch the yarns and thereby induce an addiitonal drag inthem at the proper times. While snappers function satisfactorily invariantly tensioning yarns of the higher counts, their action is toosevere on the fine gauge yarns employed in the knitting of the chiffonweight stockings now in vogue, with consequent causation of frequentruptures of the yarns, and in turn, of press-offs" of the fabrics fromthe needles of the knitting machines.

The chief aim of my invention is to preclude the above contingencieswhich objective Irealize in practice as hereinafter more fullydisclosed, an through provision of a yarn tensioning means whichincludes arocker having spaced arms with guide eyes for the yarn, and anassociated spring element carrying a wiper, winch, incident tooscillation of the rocker is brought into contact with the span of theyarn extending between the two guide eyes thereby to induce theadditional drag at the required times without straining the yarn to thepoint of breakage.

Another object of my invention is to attain the foregoing advantageswith a tensioning device which can be substituted in piace of theregular snap tensions, and which is operable by the standard mechanismprovided in the machines for actuating the snappers withoutnecessitating any changes whatever either in the construction orfunctioning of such mechanism.

Other objects and attendant advantages will appear from the followingdetailed description of the attached drawings, wherein Fig. I is askeletonized fragmentary cross sectional view of a fiat knitting machineembodying my improved yarn tensioning means.

Figs. 11 and IE are views on a larger scale corresponding to Fig. I andrespectively showing the cooperating elements of the yarn tensioningmeans in different positions; and

Fig. IV is a detail sectional view taken as indicated by the arrowsIV-IV in Fig. III.

The machine illustrated in Fig.1 of these draw- 5 lugs for convenienceof exemplifying my invention is of well known construction, its needles5 being mounted in a bar 2, which, incident to the knitting, is actuatedin the usual way to move the needles in relation to the sinkers andknock- 10 over bits indicated respectively at 3 and i. As ordinarily,the sinkers 3 are suitably guided for horizontal sliding movement towardand away from the needles I, in a stationary head 5 supported by one ofthe longitudinal rails 6 of the machine frame. One of the yarns used inthe knitting is indicated at "i, the same being drawn from a supply cone8 within a humidifier box 9 which is mounted on a platform 60 attachedto the horizontal base portions of upright brackets 29 at intervalsalong the machine frame, one of i which brackets is shown at H. Also, asusual, the knitting yarns are fed to the needles by individual carriersaflixed to longitudinal bars 92 which are slidably supported for endwisemove- 535 ment in other stationary brackets such as shown at it likewisearranged at intervals along the machine frame, the guide for the yarn ibeing shown at it. In leaving the cone 8, the yarn. l passes through aneye it in the top of the hu so midifier box a, then over one of a numberof studs it on an arm E'l adjustably secured to the bracket in at therear, then through 2. moistener it at the top of the bracket ll, andthen over one of a number of studs 09 on another arm 2t adjustablysecured to said bracket at the front. As a result of its travel over thecircuitous course defined by these guides, a definite amount of normaltension is maintained on the yarn l as well understood in the art.

The yarn tensioning means with which the present invention is moreespecially concerned comprises a rocker element El having its hub 22-adjustably clamped by means of a screw 23, to a rock shaft 2 5 which maybe one of the usual snapper rock shafts or. the machine, and which, asusual, is journaled in the top of the bracket it. From Figs. 11 and Ill,it will be observed that the rocker 29 is formed with a pair of spacedarms 25 and 25, respectively having eyes 2i, iii through which the yarnl passes. Arranged to cooperate with the rocker 28 is a flexible elementin the form of a flat spring tongue which, at one end is secured to thearm it of said rocker by means of a screw tit, and which cv rreaches thearm it.

As shown, the free end of the spring tongue 29 is bent downwardly toengage over a fixed member of the machine, which member may be the rod3| whereto the guide 'arm 20 is secured, so that said spring tongue isat all times held out of direct contact with the arm 26 of the rocker.Mounted at an intermediate point on the spring tongue 29 is a wiper 32preferably of closely compressed felted textile fiber. As the rocker 2|moves from the position of Fig. II to that of Fig. III, the wiper 32 isbrought into contact with the span of the yarn 1 extending between theeyes 21,28 in the arms 25, 26, and in this way-additional drag isimposed upon the yarn I.

For the purpose of actuating the yarn tensioning devices of myinvention, it is possible to utilize the standard snapper actuatingmechanism of the knitting machine. As delineated in Fig. I, thismechanism includes an arm 33 on the rock shaft 24 connected by adownwardly extending link rod 34 to one end of a lever 35 which isfulcrumed at 36 on a fixed bracket 31 of the machine frame, and which atits opposite end carries a roller 38 arranged to cooperate with a rotarycam 39 on the main cam shaft 40 of the machine, said roller being heldin contact with the periphery of the cam by means of a spring shown at4|. It is, of course to be understood that the cam 39 is so positionedon the cam shaft 40 as to effect actuation of the yarn tension of myinvention to cause additional tension to be imposed on the yarn T as theyarn carrier I 4 approaches the limits of its travel in oppositedirections; and moreover that the elements 2| and 29 are intended to beduplicated for the other yarns which may be employed in the knitting.

From the foregoing, it .will be apparent that I in the construction oroperation of the usual snapper actuating mechanisms of the machines.Having thus described my invention, I claim:

1. Yarn tensioning means for knitting machines including an element withspaced eyes through which the yarn passes on its way to the needles ofthe knitting machine; an attached flexible tongue element carrying awiper; and means for periodically moving the two elements relativelyduring feeding of the yarn so that the wiper is broughtinto contact witha free span of the yarn between the eyes aforesaid to change the path ofthe yarn and correspondingly vary its tension.- f

2. Yarn tensioning means for knitting-machines according to claim 1,wherein the wiper is of yielding materiaLlike felt.

3. Yarn tensioning means for knitting machines including a rock shaft; arocker on said shaft having a pair of arms with eyes-through which theyarn passes enroute to the needles of the knitting machine; a springtongue secured to one of the arms of the rocker and overreaching theother arm thereof; a wiper medially mounted on. the spring tongue; afixed element for supporting the free end of the spring tongue andholding it away from the overreached arm of the rocker but permittingsaid wiper to be periodically brought into contact with a free span ofthe yarn between the eyes aforesaid as the rocker isoscillated duringthe knitting thereby to change its path and correspondingly vary itstension.

4. Yarn tensioning means for flat knitting machines in which yarn isdirected to a series of needles by a longitudinally reciprocatingcarrier including a rock shaft; a rocker on said shaft having a pair ofspaced arms with eyes through which the yarn passes on its way'to thecarrier; a spring tongue secured to'oneof the arms of the rocker andoverreaching the other arm thereof; a wiper medially mounted on saidtongue; a fixed element for supporting the free end of the springvtongue and normally holding it away from the overreached arm of therocker but permitting the wiper to be periodically brought into contactwith a free span of the yarn between the eyes aforesaid to change thepath of the yarn and correspondingly increase its tension; and means forrocking the shaft to bring about the increased tension upon the yarn asthe yarn carrier approaches the limits of its travel in oppositedirections.

' EMILfl. BERGER.

